Slowly resolving and nonresolving pneumonias.

Nonresolving or slowly resolving pulmonary infiltrates are a clinical diagnostic challenge for physicians. It is important to differentiate slowly resolving from nonresolving pneumonias because the causes of each of these two clinical entities are different. In general, slowly resolving pneumonias are due to antimicrobial or host defense factors. Nonresolving pneumonias are usually noninfectious and usually require invasive diagnostic techniques to confirm the diagnosis. The most common clinical error made in approaching patients with nonresolving or slowly resolving pulmonary infiltrates is to treat the patient with different antibiotics over an extended period of time. Non-resolving or slowly resolving pneumonia should prompt the clinician to intensify diagnostic efforts to arrive at an etiologic diagnosis. The response should not be extended to polypharmacy since antibiotic-related causes of failure in treating problems resulting in slowly resolving pneumonia are one of the least common reasons for this clinical presentation.